The invention relates to an electrode arrangement for stimulating the heart by mans of an implantable cardiac pacemaker which generates electrical pulses.
In the treatment of various chronic disturbances in cardiac rhythm, implanted cardiac pacemakers are in use, in conjunction with stimulating electrodes disposed on an intracardial electrode catheter and positioned on the inner wall of the heart; the stimulatable cardiac tissue is excited by way of these electrodes. The design of the pacemakers and the associated electrode lines has undergone increasing perfection, and numerous technical solutions have been found for anchoring the electrode catheters to the heart wall--both in the ventricle and in the atrium-and substantial practical improvements have in fact successfully been attained.
Nevertheless, even today, electrode dislocations, which lead to a worsening of contact with the stimulatable tissue on the inner wall of the heart, or even a loss of such contact, and consequently at least a substantial increase in the stimulation threshold and thus increased current consumption by the pacemaker and reduced service life, and in the worst case cause the pacemaker to become nonfunctional, are among the most important complications in pacemaker therapy.
In addition, the fact that up to the present the stimulating pulses of an implanted pacemaker are transmitted to the stimulatable muscle tissue of the inner wall of the heart in the lower region of the ventricle or atrium are transmitted via electrodes attached to the walls is also necessarily unsatisfactory, for fundamental physiological reasons.
Floating electrodes, on the other hand, have been unable so far to assure stimulation with sufficient safety that regular use would be appropriate.